diff --git a/NAMESPACE b/NAMESPACE
index db250ef..0cb96c9 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -2,3 +2,15 @@
 
 export(isoband_terra)
 export(isoline_terra)
+importFrom(isoband,iso_to_sfg)
+importFrom(isoband,isobands)
+importFrom(isoband,isolines)
+importFrom(sf,st_sf)
+importFrom(sf,st_sfc)
+importFrom(terra,as.array)
+importFrom(terra,crs)
+importFrom(terra,vect)
+importFrom(terra,xFromCol)
+importFrom(terra,yFromRow)
+importFrom(utils,head)
+importFrom(utils,tail)
diff --git a/R/isoraster-package.R b/R/isoraster-package.R
new file mode 100644
index 0000000..a65cf64
--- /dev/null
+++ b/R/isoraster-package.R
@@ -0,0 +1,6 @@
+#' @keywords internal
+"_PACKAGE"
+
+## usethis namespace: start
+## usethis namespace: end
+NULL
diff --git a/R/isoraster.R b/R/isoraster.R
index bbf1629..793cbfa 100644
--- a/R/isoraster.R
+++ b/R/isoraster.R
@@ -16,6 +16,10 @@
 #' for isoband_terra a table of spatial polygons with 'lo' and 'hi' contour values
 #' @export
 #' @aliases isoband_terra
+#' @importFrom terra as.array xFromCol yFromRow vect crs
+#' @importFrom sf st_sfc st_sf
+#' @importFrom utils head tail
+#' @importFrom isoband iso_to_sfg isolines isobands
 #' @examples
 #' isoline_terra(rast(volcano))
 #' isoband_terra(rast(volcano), lo = 100, hi = 150)